Signature tool in Xamarin Viewer

The Tools package comes with a basic DigitalSignature tool that allows signing with a specific keystore and password. The DigitalSignature tool can be used with the UI components such as DocumentActivity and PdfViewCtrlTabHostFragment2 . You can also use the tool with PDFViewCtrl through ToolManager .

By default, the signature tool does not sign with a certificate. Certificate-based signatures can be enabled using ToolManagerBuilder which will add a certificate picker and password input field to the signature UI flow.

Alternatively you can define a certificate file and password in ToolManagerBuilder. This will disable the additional signing flow for digital signatures and use the specified certificate instead.

var tmBuilder = ToolManagerBuilder.From()
  .SetUseDigitalSignature(true)
  // Optionally specify a default certificate file and password
  .SetDigitalSignatureKeystorePath("my_keystore_path")
  .SetDigitalSignatureKeystorePassword("my_keystore_password")
var builder = ViewerConfig.Builder()
var config = builder
  //...
  .ToolManagerBuilder(tmBuilder)
  .Build()

The signed document is then saved to a separate file.